Dry cell



i No Drawing.

Patented Aug. 2, 1927.

VICTOR .VYNGVE, 70F. sor aur oRANenfnEw JERsnY, Assrenon, BY lvrnsnn fassrenmnn'rs, T0 narronnnoaanoncolyrranx, 1nd, or new, YORK, N. Y., A 0032035;

' TION OF NEW YORK.

Application filed January This invention relates to dry cells and more particularly to new and useful 11nprovements in the method of preparing the depolarizing mixture of dry cells.

As wellknown, the depolarizing mixture of dry cells is usually prepared by intimately mixing together a depolarizer such as manganese dioxide and some carbonaceous or other conducting material such as graphite.. The intimate. intermixture is accomplished either by stirring together materials that had been ground to the proper degree of fineness, or by milling the manganese ore together with the graphite until the proper fineness is secured. Usually, ammonium chloride and a solution containing zinc chloride with or without ammonium chloride is added to this mixture.

These methods of making dry batteries are not entirely satisfactory. When, in order to avoid separate milling, jointmilling of the materals is resorted to, then,,owing to the much greater hardness of the manganese ore, the graphite or other carbonaceous material that is being milled with it will be reduced to a finer condition than required for best results. If a mixture of 300 parts of manganese dioxide ore and 100 parts of graphite of suitable grade are milled together, then in the resultant mix-- ture and graphite will be extremely fine, and as a result or this the battery in which such mixture is used will have a lower amperage than would be the case with coarser graphite constituents in the mixture. Furthermore,

graphite is bulky material and occupies a volume of mill space equal to that occupied by manganese dioxide of much greater weight.

In order to eliminate the above enumerated disadvantages, in accordance with the present invention a relatively small amount of graphite is milled with manganese ore.

' Both materials should be in dry condition to insure thorough breaking up of th graphite particles. For example, 880 parts of maganese ore is milled in a ball or pebble mill together with 50 parts of graphite of suitable quality until at-least 95% of the mixture'passes through a 200* mesh screen. ,.The milled material which is not as yet suitable for use as a battery mixture is then re- -moved from the mill and portions of the milled product are mixed-with an additional 12, 1925. Serial No. 1,921.

amount of coarser graphite. A suitable ratio would be 42 parts of milled mixture and 7.5 parts of relatively coarse graphite. The resulting product is then made into a battery mix in accordance with any of the for manganese dioxide ore, and that any suitable conducting carbonaceous. material The may be substitutedtor the graphite. ratios of 7.621 and 5.621, assumed in the above example, give excellent results but may be Varied to suitparticular requirements. T

that I claim is:

1. The method of preparing dry cell mixture which consists in milling together depolarizing and ordinary carbonaceous materials, the latter being less in quantity than is required in the mix, and then adding the balance of the required carbonaceous material in I ordinary product.

2. The method'of preparing dry cell mixture which consists in milling together man-v ganese dioxide and relatively coarse graphite in dry condition, the latter being less in quantity than is required in the mix, and then adding the balance of the required form to the milled graphite in' relatively coarse form to the milled product.

3. The method of preparing dry cell mixture whichconsists in milling together manganese dioxide ore and a quantity of graphite less than is required for the mixture to I comminute the ore and graphite, and then adding some relatively coarse graphite to the milled product. f i

4. The method of preparing dry cell mixture which consists in milling together to the desired degree of fineness manganese dioxide ore and ordinary graphite, the ratio 7 addingto 5.6 psirts of the. milled mixture one; manganesedioxide and, graphite particles 7 part of reeltivelyec oarse graphite; and then adding enough-relatively coarse l0 6. The method of preparing dry cell graphite to complete the qiiantitythereof re-' 'mixture whieh comprises mixing together quiredfor the mix.

particles of manganese dioxideand graphite In -testimony whereof I have signed-my 0f--given-'size,-the quantityfofgraphite being name; to this '-specifieatibn,' -thi n mh -ua 7 less than is required in the finished mix, milof January, 1925; I

ling the mixture to reduce the size of the VICTOR YNGVE. e 

